id	title
built-in-types	Built-in types

Built-in Types

TypeSpec Standard Library provide some built-in types that can be used to build more complex types.

Built in types are related to each other according to the rules described in type relations.

Numeric types

Type	Range	Description
`numeric`		Parent type for all numeric types
`integer`		A whole-number
`float`		A binary number
`int64`	`-9,223,372,036,854,775,808` to `9,223,372,036,854,775,807`	A 64-bit integer
`int32`	`-2,147,483,648` to `2,147,483,647`	A 32-bit integer
`int16`	`-32,768` to `32,767`	A 16-bit integer
`int8`	`-128` to `127`	A 8-bit integer
`safeint`	`−9007199254740991 (−(2⁵³ − 1))` to `9007199254740991 (2⁵³ − 1)`	An integer that can be serialized to JSON
`uint64`	`0` to `18,446,744,073,709,551,615`	Unsigned 64-bit integer
`uint32`	`0` to `4,294,967,295`	Unsigned 32-bit integer
`uint16`	`0` to `65,535`	Unsigned 16-bit integer
`uint8`	`0` to `255`	Unsigned 8-bit integer
`float32`	`±1.5 x 10⁴⁵` to `±3.4 x 10³⁸`	A 32 bit floating point number
`float64`	`±5.0 × 10⁻³²⁴` to `±1.7 × 10³⁰⁸`	A 64 bit floating point number
`decimal`		A decimal number
`decimal128`	34 decimal digits with an exponent range from `-6143` to `6144`	A 128 bit decimal number

Type	Description
`plainDate`	A date on a calendar without a time zone, e.g. "April 10th"
`plainTime`	A time on a clock without a time zone, e.g. "3:00 am"
`utcDateTime`	A date and time in coordinated universal time (UTC), e.g. "1985-04-12T23:20:50.52Z"
`offsetDateTime`	A date and time in a particular time zone, e.g. "April 10th at 3:00am in PST"
`duration`	A duration/time period. e.g 5s, 10h

Type	Description
`bytes`	A sequence of bytes
`string`	A sequence of textual characters
`boolean`	Boolean with `true` and `false` values
`null`	Null value
`Array<Element>`	Array model type, equivalent to `Element[]`
`Record<Element>`	Model with string keys where all the values have type `Element` (similar to `Map<string, Element>` in TypeScript or `Dictionary<string, Element>` in .Net)
`unknown`	A top type in TypeSpec that all types can be assigned to. Values that can have any type should be assigned this value (similar to `any` in JavaScript)
`void`	A function/operation return type indicating the function/operation doesn't return a value.
`never`	The never type indicates the values that will never occur.

Built-in types that are known string formats

Type	Description
`url`	A url String